Water-heater.



Patented January 3, 1905.

arena Orricn.

ROBERT H. FRASER, OF BOSTON, MASSACHUSETTS.

WATER-HEATER.

SPECIFICATION forming part of Letters Patent No. 779,154, dated January 3, 1905.

I Application filed March 28, 1904. Serial No. 200,807.

To a/ZZ whom, it may concern:

Be it known that I, ROBERT H. FRASER, of

ABoston, in the county of Suifolk and State of construction and combination of parts substantially as hereinafter described and claimed. Of the accompanying drawings, forming a part of this specification, Figure 1 represents a vertical longitudinal section of a portion of a dry back Scotch boiler having my improved heater applied thereto. Fig. 2 represents a section on line 2 2 of Fig. 1.

The inner and outer shells of the Scotch.

boiler are represented at 10 and 11, respectively, the tubes at 12, the rear wall at 13, and the bridge-wall at 14. Extending lengthwise of the waterspace between the two shells and in the lower portion of said space is a perforated pipe 15, having a branch 16 extending through the bottom of the boiler and connected by a coupling 17 with a pipe or conduit 18, leading upward, outside of the rear wall 13, and connected by a branch 19 with the inner chambers 2O of the compound steel castings A, suitably secured to or supported by the rear wall 13.

Each of the cast-steel compound chambers A is formed with an inner chamber 2O and an outer chamber 21. A row of tubes 22, having closed outer ends,connect with the outer chamber 21 and pass through the rear wall 13 into the combustion-chamber of the boiler. Within each tube 22 is an inner tube 23, having an open end and projecting from and connected with the inner chamber 2O of the castl ing A. The two outer chambers 21 communicate by pipes 24 with a T-coupling 25, from which a pipe 26 leads around the side of the boiler and passes therethrough, so as to discharge water into the upper portion of the water-space of the boiler.

It will now be readily understood that when the boiler is in use the heating of the water that is in the tubes 22 and 23 will cause a circulation as follows: The water leaving the boiler by means of the perforated pipe 15 passes through the conduit 18 and the branch 19 into the inner chambers 2O of the castings A, then through the open-ended tubes 23,then returning through the annular spaces inclosed between the tubes 22 and 23 into the outer chamber 21 of each casting, and from the latter through the pipes 24 and 26 to the upper portion of the boiler. The water as it circulates is most effectively heated by the eX- posure of the rows of tubes which project into the combustion-chamber of the boiler.

By connecting a Coldwater-supply pipe 27 with the coupling 17 below the boiler, which supply-pipe may either be connected with a pump or to an injector device, the means above described may be employed for heating feed water in a manner that will be' obvious. Vhen feed-water is to be forced into the boiler, it will simply pass through the conduit 18 and from there through the heater and then into the upper portion of the water-space of the boiler in the same manner that has been above vdescribed in connection with the circulation of the boiler-water.

It will be understood that if the connections 18, 24, and 26 were steam-pipes instead of water-pipes the tubes 22 and 23, which project into the combustion-chamber of the boiler, would practically form a superheater for the steam.

The invention is applicable also to other Y types of boilers, such as return tubular boilers.

1. The combination with a boiler, of a plurality of inner and outer tubes projecting through the rear wall thereof, the outer tubes having closed ends and the inner tubes having open ends, and means for causing a fluid to pass through said inner tubes and through the lLnnular spaces formed between the inner and outer tubes.

2. The combination with a. boiler having e combustion-chamber at one end thereof, of

easings or Castings formed with inner and outer chambers at the rear of the boiler, tubes having olosed ends projecting from said outer chambers through said rear wall, tubes having open ends inolosed within the iirst-rnentioned tubes and Connecting with the inner chambers of said oasings, and connections whereby water may be drawn from the'lower portion of the boiler and passed through said inner and outer tubes and returned to the upper portion of the boiler.

3. rlhe combination with a boiler having e Combustion-chamber at one end thereof, of oasings or Castings formed with inner and outer chambers at the rear of the boiler, tubes having closed ends projecting from said outer chambers through said rear wall, tubes having open ends inolosed Within the first-mentioned tubes and connecting with the inner Chambers of said easings, and connections whereby water may be drawn from the lower portion of the boiler and passed through said inner and outer tubes and returned to the upper portion of the boiler, Connections being also provided for supplying feed-water to the conduit or pipe leading to the said oasings or Castings.

In testimony whereof I have aiiixed my signature in presence of two witnesses.

. ROBERT H. FRASER. Witnesses:

C. F. BROWN, E. BATGHELDER. 

